W supported on g-CN manifests high activity and selectivity for N2 electroreduction to NH3

Abstract

In comparison to the conventional Haber–Bosch (H–B) process, electrochemical N₂ fixation is a more promising approach for NH₃ production due to its environmentally-friendly process and feasibility under ambient conditions. In this work, by means of first-principles calculations, a series of transition metal (TM) atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo and W) supported on a new kind of graphitic carbon nitride (g-CN) were evaluated for N₂ fixation. The results indicate that the thermally and dynamically stable W/g-CN could be a promising candidate for the N₂ reduction reaction (NRR) with high catalytic activity, with the onset potential being only 0.34 V. In addition, W/g-CN shows high selectivity to the NRR with the effective suppression of the hydrogen evolution reaction (HER), with the Faradaic efficiency (FE) being 100%. It can be highlighted from this work that the metal–support interaction, which alters the local geometric and electronic features, is determinative for the NRR performance, thus providing prospects for the design of effective NRR catalysts.